Field of the Invention
The present invention relates to a multilayer ceramic capacitor constituted by a capacitor body of roughly rectangular solid shape, which has a first external electrode and a second external electrode provided with a space between them on one of the two height-direction surfaces of the capacitor body in the length direction.
Description of the Related Art
As a way to make a multilayer ceramic capacitor smaller while increasing its capacitance at the same time, a structure is known where a first external electrode and a second external electrode are provided with a space between them on one of the two height-direction surfaces of a capacitor body of roughly rectangular solid shape in the length direction (such as Patent Literature 1 described below). As a supplemental note on this structure, the capacitor body has a built-in capacitive part comprising multiple first internal electrode layers and multiple second internal electrode layers stacked alternately in the width direction with dielectric layers in between. Also, the lead part of each first internal electrode layer is exposed on one of the two height-direction surfaces of the capacitor body, with this exposed part connected independently and electrically to the first external electrode; while the lead part of each second internal electrode layer is exposed on one of the two height-direction surfaces of the capacitor body, with this exposed part connected independently and electrically to the second external electrode.
Because its first external electrode and second external electrode are provided on one of the two height-direction surfaces of the capacitor body, this multilayer ceramic capacitor can prevent, to the maximum extent possible, the external dimensions of the capacitor body from being limited by the first external electrode and second external electrode, compared to when the external electrodes have an L-shape, horizontal U-shape, quadrangular cylinder shape with bottom, or the like. This means that, even when the external dimensions of the multilayer ceramic capacitor are small, the capacitor body can be designed with the maximum possible external dimensions, which in turn allows the contour dimensions of the first internal electrode layer and second internal electrode layer to increase, respectively, thereby increasing the facing area of the internal electrode layers and achieving a larger capacitance as a result.
However, the present inventors realized the following problems. That is, a multilayer ceramic capacitor with its first external electrode and second external electrode provided on one of the two height-direction surfaces of the capacitor body generally exhibits weaker separation strength with respect to the first external electrode, and also to the second external electrode, compared to when the external electrodes have an L-shape, horizontal U-shape, quadrangular cylinder shape with bottom, or the like.
To be specific, the surfaces of the first external electrode and second external electrode contacting one of the two height-direction surfaces of the capacitor body each have a planar shape, so when a force acts upon these contact surfaces after the multilayer ceramic capacitor has been mounted on a circuit board, there are concerns that the first external electrode and second external electrode may each displace relative to the capacitor body and end up separating from the capacitor body. Particularly when the multilayer ceramic capacitor is made smaller, an extra factor of having to ensure a space between the first external electrode and second external electrode to prevent short-circuiting adds to the difficulty of allowing the first external electrode and second external electrode to contact one of the two height-direction surfaces of the capacitor body over a wide area, and this makes the aforementioned separation phenomenon more apparent.
Any discussion of problems and solutions involved in the related art (particularly those discussed above) has been included in this disclosure solely for the purposes of providing a context for the present invention, and should not be taken as an admission that any or all of the discussion were known at the time the invention was made.